v0.4.0

closes #32
closes #33

macros/src/analyze.rs

@@ -1,77 +1,243 @@
-use std::cmp;
-use std::collections::HashMap;
+use std::{
+    cmp,
+    collections::{HashMap, HashSet},
+};
 
-use syn::Ident;
+use syn::{Attribute, Ident, Type};
 
-use check::App;
+use syntax::{App, Idents};
 
 pub type Ownerships = HashMap<Ident, Ownership>;
 
+pub struct Analysis {
+    /// Capacities of free queues
+    pub capacities: Capacities,
+    pub dispatchers: Dispatchers,
+    // Ceilings of free queues
+    pub free_queues: HashMap<Ident, u8>,
+    pub resources_assert_send: HashSet<Box<Type>>,
+    pub tasks_assert_send: HashSet<Ident>,
+    /// Types of RO resources that need to be Sync
+    pub assert_sync: HashSet<Box<Type>>,
+    // Resource ownership
+    pub ownerships: Ownerships,
+    // Ceilings of ready queues
+    pub ready_queues: HashMap<u8, u8>,
+    pub timer_queue: TimerQueue,
+}
+
+#[derive(Clone, Copy, PartialEq)]
 pub enum Ownership {
-    /// Owned or co-owned by tasks that run at the same priority
+    // NOTE priorities and ceilings are "logical" (0 = lowest priority, 255 = highest priority)
     Owned { priority: u8 },
-    /// Shared by tasks that run at different priorities.
-    ///
-    /// `ceiling` is the maximum value across all the task priorities
     Shared { ceiling: u8 },
 }
 
 impl Ownership {
-    pub fn ceiling(&self) -> u8 {
+    pub fn needs_lock(&self, priority: u8) -> bool {
         match *self {
-            Ownership::Owned { priority } => priority,
-            Ownership::Shared { ceiling } => ceiling,
-        }
-    }
+            Ownership::Owned { .. } => false,
+            Ownership::Shared { ceiling } => {
+                debug_assert!(ceiling >= priority);
 
-    pub fn is_owned(&self) -> bool {
-        match *self {
-            Ownership::Owned { .. } => true,
-            _ => false,
+                priority < ceiling
+            }
         }
     }
 }
 
-pub fn app(app: &App) -> Ownerships {
-    let mut ownerships = HashMap::new();
+pub struct Dispatcher {
+    /// Attributes to apply to the dispatcher
+    pub attrs: Vec<Attribute>,
+    pub interrupt: Ident,
+    /// Tasks dispatched at this priority level
+    pub tasks: Vec<Ident>,
+    // Queue capacity
+    pub capacity: u8,
+}
 
-    for resource in &app.idle.resources {
-        ownerships.insert(resource.clone(), Ownership::Owned { priority: 0 });
-    }
+/// Priority -> Dispatcher
+pub type Dispatchers = HashMap<u8, Dispatcher>;
 
-    for task in app.tasks.values() {
-        for resource in task.resources.iter() {
-            if let Some(ownership) = ownerships.get_mut(resource) {
-                match *ownership {
-                    Ownership::Owned { priority } => {
-                        if priority == task.priority {
-                            *ownership = Ownership::Owned { priority };
-                        } else {
-                            *ownership = Ownership::Shared {
-                                ceiling: cmp::max(priority, task.priority),
-                            };
-                        }
-                    }
-                    Ownership::Shared { ceiling } => {
-                        if task.priority > ceiling {
-                            *ownership = Ownership::Shared {
-                                ceiling: task.priority,
-                            };
+pub type Capacities = HashMap<Ident, u8>;
+
+pub fn app(app: &App) -> Analysis {
+    // Ceiling analysis of R/W resource and Sync analysis of RO resources
+    // (Resource shared by tasks that run at different priorities need to be `Sync`)
+    let mut ownerships = Ownerships::new();
+    let mut resources_assert_send = HashSet::new();
+    let mut tasks_assert_send = HashSet::new();
+    let mut assert_sync = HashSet::new();
+
+    for (priority, res) in app.resource_accesses() {
+        if let Some(ownership) = ownerships.get_mut(res) {
+            match *ownership {
+                Ownership::Owned { priority: ceiling } | Ownership::Shared { ceiling } => {
+                    if priority != ceiling {
+                        *ownership = Ownership::Shared {
+                            ceiling: cmp::max(ceiling, priority),
+                        };
+
+                        let res = &app.resources[res];
+                        if res.mutability.is_none() {
+                            assert_sync.insert(res.ty.clone());
                         }
                     }
                 }
-
-                continue;
             }
 
-            ownerships.insert(
-                resource.clone(),
-                Ownership::Owned {
-                    priority: task.priority,
-                },
-            );
+            continue;
+        }
+
+        ownerships.insert(res.clone(), Ownership::Owned { priority });
+    }
+
+    // Compute sizes of free queues
+    // We assume at most one message per `spawn` / `schedule`
+    let mut capacities: Capacities = app.tasks.keys().map(|task| (task.clone(), 0)).collect();
+    for (_, task) in app.spawn_calls().chain(app.schedule_calls()) {
+        *capacities.get_mut(task).expect("BUG: capacities.get_mut") += 1;
+    }
+
+    // Override computed capacities if user specified a capacity in `#[task]`
+    for (name, task) in &app.tasks {
+        if let Some(cap) = task.args.capacity {
+            *capacities.get_mut(name).expect("BUG: capacities.get_mut") = cap;
         }
     }
 
-    ownerships
+    // Compute the size of the timer queue
+    // Compute the priority of the timer queue, which matches the priority of the highest
+    // `schedule`-able task
+    let mut tq_capacity = 0;
+    let mut tq_priority = 1;
+    let mut tq_tasks = Idents::new();
+    for (_, task) in app.schedule_calls() {
+        tq_capacity += capacities[task];
+        tq_priority = cmp::max(tq_priority, app.tasks[task].args.priority);
+        tq_tasks.insert(task.clone());
+    }
+
+    // Compute dispatchers capacities
+    // Determine which tasks are dispatched by which dispatcher
+    // Compute the timer queue priority which matches the priority of the highest priority
+    // dispatcher
+    let mut dispatchers = Dispatchers::new();
+    let mut free_interrupts = app.free_interrupts.iter();
+    let mut tasks = app.tasks.iter().collect::<Vec<_>>();
+    tasks.sort_by(|l, r| l.1.args.priority.cmp(&r.1.args.priority));
+    for (name, task) in tasks {
+        let dispatcher = dispatchers.entry(task.args.priority).or_insert_with(|| {
+            let (name, fi) = free_interrupts
+                .next()
+                .expect("BUG: not enough free_interrupts");
+
+            Dispatcher {
+                attrs: fi.attrs.clone(),
+                capacity: 0,
+                interrupt: name.clone(),
+                tasks: vec![],
+            }
+        });
+
+        dispatcher.capacity += capacities[name];
+        dispatcher.tasks.push(name.clone());
+    }
+
+    // All messages sent from `init` need to be `Send`
+    for task in app.init.args.spawn.iter().chain(&app.init.args.schedule) {
+        tasks_assert_send.insert(task.clone());
+    }
+
+    // All late resources need to be `Send`, unless they are owned by `idle`
+    for (name, res) in &app.resources {
+        let owned_by_idle = Ownership::Owned { priority: 0 };
+        if res.expr.is_none()
+            && ownerships
+                .get(name)
+                .map(|ship| *ship != owned_by_idle)
+                .unwrap_or(false)
+        {
+            resources_assert_send.insert(res.ty.clone());
+        }
+    }
+
+    // All resources shared with init need to be `Send`, unless they are owned by `idle`
+    // This is equivalent to late initialization (e.g. `static mut LATE: Option<T> = None`)
+    for name in &app.init.args.resources {
+        let owned_by_idle = Ownership::Owned { priority: 0 };
+        if ownerships
+            .get(name)
+            .map(|ship| *ship != owned_by_idle)
+            .unwrap_or(false)
+        {
+            resources_assert_send.insert(app.resources[name].ty.clone());
+        }
+    }
+
+    // Ceiling analysis of free queues (consumer end point) -- first pass
+    // Ceiling analysis of ready queues (producer end point)
+    // Also compute more Send-ness requirements
+    let mut free_queues: HashMap<_, _> = app.tasks.keys().map(|task| (task.clone(), 0)).collect();
+    let mut ready_queues: HashMap<_, _> = dispatchers.keys().map(|level| (*level, 0)).collect();
+    for (priority, task) in app.spawn_calls() {
+        if let Some(priority) = priority {
+            // Users of `spawn` contend for the to-be-spawned task FREE_QUEUE
+            let c = free_queues.get_mut(task).expect("BUG: free_queue.get_mut");
+            *c = cmp::max(*c, priority);
+
+            let c = ready_queues
+                .get_mut(&app.tasks[task].args.priority)
+                .expect("BUG: ready_queues.get_mut");
+            *c = cmp::max(*c, priority);
+
+            // Send is required when sending messages from a task whose priority doesn't match the
+            // priority of the receiving task
+            if app.tasks[task].args.priority != priority {
+                tasks_assert_send.insert(task.clone());
+            }
+        } else {
+            // spawns from `init` are excluded from the ceiling analysis
+        }
+    }
+
+    // Ceiling analysis of free queues (consumer end point) -- second pass
+    // Ceiling analysis of the timer queue
+    let mut tq_ceiling = tq_priority;
+    for (priority, task) in app.schedule_calls() {
+        if let Some(priority) = priority {
+            // Users of `schedule` contend for the to-be-spawned task FREE_QUEUE (consumer end point)
+            let c = free_queues.get_mut(task).expect("BUG: free_queue.get_mut");
+            *c = cmp::max(*c, priority);
+
+            // Users of `schedule` contend for the timer queu
+            tq_ceiling = cmp::max(tq_ceiling, priority);
+        } else {
+            // spawns from `init` are excluded from the ceiling analysis
+        }
+    }
+
+    Analysis {
+        capacities,
+        dispatchers,
+        free_queues,
+        tasks_assert_send,
+        resources_assert_send,
+        assert_sync,
+        ownerships,
+        ready_queues,
+        timer_queue: TimerQueue {
+            capacity: tq_capacity,
+            ceiling: tq_ceiling,
+            priority: tq_priority,
+            tasks: tq_tasks,
+        },
+    }
+}
+
+pub struct TimerQueue {
+    pub capacity: u8,
+    pub ceiling: u8,
+    pub priority: u8,
+    pub tasks: Idents,
 }